Method and apparatus for molding articles



Fb.v7, 1928. 1,658,566

FQJ. MacDoNALD METHOD AND APARATUS FOR MOLDING ARTICLES originalFiled May 19.` 1924 .s sheets-sheet 1 @E INT1 Il l; llllilllmll illf N-I In' w /zi Ilm y 1 1jmlllhmmlmii inf "MINI F. J. MaCDONALD METHOD AND APPARATUS FOR MOLDING ARTICLES Feb. 7, 1928. 1,658,566

Original Filed May 19, 1924 3 sheets-Sheet 2 Feb. 7, 1928. 1,658,566-

F. J. MacDoNALD METHOD AND APPARATUS FOR MOLDING ARTICLES Original Filed May 19, 1924 3 Sheets-Sheet 5 Inl 33 lil Illll Patented Feb. 7, 1928.

UNITED STATE/s `Pii'riizirr loi-iiicr..y

v.FRANK J. MACDONALD, OF AKRON, OHIO, ASSIGNOR TO THE B. F. GOODRIC COMPANY, 0F NEW YORIL N. Y., A CORPORATION OF NEW YORK. 1

METHOD A ND A PPARATns roi?. MOLDING ARTICLES;

"'Appiieation'nied 1in-.1yi i9, 1924, seria; No. 714,257.' VRenewed Augusteli, i927.

Y 'lhis'invention relates' to the artpof molding hollow articles or containers Such as'bat- Itery jars, for example, from plastic material such vas a vulcanizable rubbercompound, ythe present invention being in some features an improvement upon those of my following Vcopending applications: Serial N o. 697,009,

filed March 5, 1924; Serial No. 704,503, tiled April 5, 1924; and Serial No. 713,077 liled ic May 13, 1924. i

The chiefobject of my present invention isfto `provide improved `and economical procedure and apparatus for molding Containers such as battery jars, and more particularly multiple celledjars, and jars or' uneven exf ternal surface. More specilically, an object is economically, accurately and rapidly to form such containers without elaborate manipulation in the assembling of the pieces ,ci stock from which the jar is molded. A further object isv to provide for conveniently vulcanizing the container iii the shaping members in which it is molded and thereafter removing said members, and more particuiai-ly in the case of a container having uiilercutl1andles integral with its walls.

Referring to the driwiiigs'." Fig'. 1 isv an elevation or apparatus embodying and adapted to carry out my invention as applied to the molding of battery .j ars.

Fig. 2 is a section of certain parts thereof, on line 2 2 of Eig. 1.

' Fig. 3 is a perspective view of the finished battery jar.

Fig. 4 is a fragmentary vertical section of vthe apparatus -from the same view point as in Fig. 1..; n

Fig. 5 vis a horizontal section on line 5-5 of Fig. 1.

- Fig. fis a horizontal section on line 6-6 of Fig.`1. .K

Fig. 7 is a horizontal ksection on line 7-7 of Fia. 1. v

Reilerringto the drawings, the apparatus comprises a base casting centrally formed as a fluid pressure cylinder 10, said cylinder having an upwardlyiprpjecting, mandrelsupporting ram 11 therein, and being provided with an inlet-outlet upipe 10a at its 5U lower end. Integral brackets'12, 12 are formed on two opposite sides ofthe casting, and secured iii vthe respective brackets are two frame posts13, 13,'which arerconnected vat their tops by a casting 14 comprising a cross-beam portion` 14 and a central, vupstanding lHuid-pressure cylinder. 15 integral therewith. The frame posts are also connected at a lower pbsition by an apertured, rain-guiding, cross-beam member 16.

Detachably secured to thevunder side of .the cross-beam 14 is a hollow bottom-pressing member 17, dowels 18, 18 being inter# posed between the two, and the member 17 being supported by a. cotter bolt 19 driven through -an aperture in the floor of the cylinder 15, to provide a liuid tight fit, its lower end extending into a bore in the bottompressing member `17 andthe bolt and the a cotter pin or wedge key 20 which bears -member 17 being transversely apertured for against lugs such as is shown at4 21, Fig. 1,

formed on the" member 17, to support the latter.

'lhe bottom pressing member in its lower portionJ is formed with vertical external faces, in horizontal section is slightly smaller than the external bottom face of the jar, andis formed with two steam chambers 22, 23, which are in Vcorr'imunicatio'n with each other at their lower ends asindicated' by the arrow in Fig. 4, the chamber 22 being pro- `vided. with an inlet pipe 24 and the chamber 23 with an outlet pipe 25 for circulating a heating fluid Asuch as steam through them.

A recess 26 is formed' in the bottom face of the member 17, and in said recess is a .block 27 secured tothe member 17 by screw bolts such "as-28 and formed with vertical grooves in whichare secured, by a bolt passing through the block, a' pair of spring clamps 30, 30 adapted to latch in position against the bottom of the member 17 a bottom-pressing plate 31 having undercut re# cesses to receive said clamps, said bottomressing plate having itsfvertical or 'edge aces Hush with the vertical faces of the member 17."

The mandrel-supporting ram, 11, is sldtted from its upper end to provide a pair of `forks 113,11, which straddle and are guided by a cross-piece 32 bridging` the `aperture in the cr'osslbeam 16 through which the ram slides..

4The 'upper end facesmof the forks 11ya of the rain are provided with respective dowels, 33, 33 for, positioning-thereona mandrel-supporting plate 34 (Fig. 4,)earpyingthree holn lowed..mandrels 35, 36, 37 adapted to Inld the respective cells of a three celled battery jar, said mandrels being so formed as to inlil tert at their bases and stand a art in their upper, molding portions to provide space for the partitions 38, 38 of the jar.

For bringing successive mandrel-supporting plates, witli mandrels thereon, into position to be engaged and raised by the ascendin" ram, a horizontally-swinging arm or table 39 is pivoted on one of the frame posts 13, its hub bearing upon the cross-beam 16. Said table is recessed at one side, at 40, 40, to admit the respective forks 11 of the ram as the latter rises to lift the mandrel assembly from said table, and the part of said table lying between the recesses 40 constitutes a tongue 41, the u per face of which is provided with dowe s 42, 42 adapted to occupy holes such as 43 in the mandrel-supporting plate 34, Fig. 4, to position said late for the reception of the dowels 33, 33 o the ram, the table 39 being adapted to be stopped in its swinging movement in one direction by abutting against the forks of the ram, and 1n the other direction by a stop 39. on the post13.-.. y

The apparatus as here shown' is adapted for use w1th maridrels of only one dimension lengthwise ofthe 'ars partitions, but the Ytable 39 is provide with mandrelositioning means which may be adjusted or mandrels of different length transversely ,of the partitions. Said means comprises an L- -sha ed gauge 44, one arm of which is formed witii a slot 45 occupied by a clamping bolt 46 rising from the table, and the other arm of the auge is formed with a number of bolt ho es 47, 47 which may be selectively registered with appropriately le, for securing the gauge in dierent positions transvers'ely of the mandrels, by means of a bolt 49 occupying the registered bolt holes. The cross-beam 1 6 is similarl provided with an L-shaped gauge 50 whicli7 1s formed with. a slot 51 occupied by a clamping bolt 52 rising from said cross-beam, andsaid'gauge is also formed with a series of bolt holes 53, 53 which may be selectively registered with apertures in the cross-beam, for securing the gauge 50-in dilerent positions transversely of the mandrels, by means of a bolt 54 occupying the registered bolt holes.A The uges 4,4 and 50 are thus adapted to cause t e mant'V-.to fit snugly together and to position them upon theplate 34 when the table 39, with the late and mandrels thereon, is swung into elivering position against the forks of the ram 11.

Means are provided for telescoping a sectional, through-cavity mold, from below, with the bottom-pressing plate 31 and member 17, andthen moving said mold downward with the flowing stock as a ma of rubber compound 55, Fi 1, is pressed between the mandrels an the plate 31 and y positioned bolt I hotles such as 48, 48 in the ta side plates 57,' 57 formed with vertical grooves on their adjacent faces to receive tongues 58, 58 formed on the edge faces of interposed 'side plates 59, 59, (Fig. 6), the first pair of plates being clamped upon the second air y cotter bolts 60, 60 mounted in the prolecting margins of the plates 57 and provlded with cotters or wedge-keys 61, 61. All of the mold platesare, formed with internal flanges such'as 57, 57* (Fig. 4) at the top and with similar lanfes such as 57 b, 57 atthe bottom, to it against the bottom-pressing member 17 and the mandrel assembly respectively to prevent escape of stock.

For manipulating the successive molds, a cross-head 62, formed with a rectangular central aperture 63 (Fig. 5) to accommodate the bottom-pressing member 17, but ada ted to bear upon the 4ends of the mold p ates 57, is formed with apertured end portions or ears which are occupied, with a sliding fit, by respective sleeves 64, 65, slidably mounted upon the frame posts 13, theupper ends of lsaid sleeves having secured thereon, by set screws 66, 66 respective threaded collars 66, 66 adapted to be adjusted to hold said sleeves at different elevations with respect to said cross-head. The latter is adapted to be raised and lowered by a pair of supporting bars 67, 67 connecting it with a yoke 68 mounted upon the u per end of a piston rod 69 rising from t e c linder 15 and provided with a piston 70 t erein, said cylinder being provided withv pressure luidpipes 71, 7 2,or actuating said piston in both directions. 62, 62. ,are stop collars clamped upon the frame posts 13 to limit the upward movementv of the crosshead 62. v

Pivoted upon the sleeve 64 and adjustably supported by a threaded collar 73 on the lower end of said sleeve is a two-armed turret 74, each arm of which is formed with a horizontal slot, as at 75, Fi 1 andin said slot are adjustably mounte the threaded stems 76, 76 of a pair of horizontal, moldsupporting brackets 77, 77 -said threaded stems being provided with cap-nuts 76, 76. Said brackets are so formed and so spaced apart as to support the mold while permitting the passage of the mandrels upward thereinto, the mandrels passing between said arms, and the latter are formed with rounded lower, inner corners, as shown at 78, 78, to center the mandi-els and hold them together as they ass'upward. between said brackets, into t e niold. Each of the brackets' is formed with a lug 79 and the the moldvupon said brackets.

The turret 'T4-is adapted to be turned on the sleeve 64 'and collar 73, the latter being providedwith a set screw 73a to prevent its rotation, to bring successive molds into position below the bottom-pressing member,

17, whenthe ram 11 and the turret-are in their lowermost positions, so that the mold may be raised into telescoped relation to said bottom-pressing member when the 15 cross-head 62 is elevated by the cylinder 15.

For stopping the turret in suchvposition and preventing its unintended rotation thererom, a cam latch 82, supported by a collar 82a screwed upon the sleeve 65 and provided 2,13 with a set screw 65a, is keyed upon thefsleeve 65, is provided with a handle 83, and is adapted to coact with latching projections 84,Y 84 on the respective arms ot the turret, under the force of-a pull spring 85, Fig. 5,

connecting a stud 86 on the sleeve 1'5 with a Stud 87 on the cross-head 62.

The sectional mold here shown is adapted t0 shape a battery ar having externally ribbed or reinforced corners or margins as shown at 88, 88, Fig. 3, and 'with integral handles` 89, 89 at the ends ot' the jar. 'the mold plates 57 being formed with undercut recesses 90, 90 Fig. 4, to form said handles, and all of the mold plates being formed with suitable recesses as at 91, 91, Fig. 4, to mold the ribs 88. 92, 92 are vents for such recesses, to prevent the entrapping of air in the molding process.A

In the operation ofthe apparatus, the ram 11 and the assembly which includes.- the cross-head 62 andV turret 74 being in their lowermost positions, as they are at the end` of each :molding operation, and the table 39 v being turned out of the way, an empty mold is mounted upon the outer arm of the turret and the latter is turned to bring said 4mold under the bottom-pressing member 17, and to carry away the preceding mold, wlth a molded jar and the mandrels therein, for 460removal at the loading and unloading position. The cylinder 15 is then actuated'to liftr the empty mold and telescope A1t with the bottom-*pressing member; as shown' in" Fi 1. set of mandrels is then mounted upon the plate 34 on the table 39, against the gauge 44, the partition blanks being inserted between the mandrels, and said table is turned to bring the plate 34and the manJ i i drels thereon into position over the ram 11,

lthe mandrels being accurately positioned `by ,the coaction of the gauges 44 and 50. .The block of rubber stock 55, at a suitablev temperature, is then mounted upon the man- 55 "drels as shown in Figrlgand the cylinder 10 is actuated to raise the ram 11, which picks up the mandrel assembly as it ascends, and presses the stock between said mandrels and the plate 31 on the bottom-pressing member 17, within the lower end of the mold, whose lower margin clearly tits the set of mandi-els. The massot' stock is thus caused to coalesce wit-h the partition stock 56 andto take the shape of the space defined by th'c mandrcls, the mold and the plate 31.

The cylinder 15 is then actuated to lower the mold, while the stock is compressed by the yielding force of the ram 11, which causes the stock to How directly from the mass into the handle recesses 9() and to continue to flow into the space between the mandrels and the moldes the latter continues to descend. The downward 'movement of the mold, -along with the growing wall of stock, results in less friction in the stock and against the mold than would be present in molding a similarly shaped article in a one-piece mold, and thus permits the' necessary flow of stock without such high pressure therein4 as to cause displacement of the man drels with relation to the mold, or require great forceto .flow the stock the length of the mandrels.

In the particular apparatus here shown,

adapted for making an article having thick wallportions, the steek may be forced upward, towardand into the recesses 91, be- I 'llore the upper part of the mold has descended to the level of the unformed mass ot stock, as in the condition shown in Fig. 4, but this does not nullify theadvantage of effecting movement of the mold in the direction of the general and ultimate How of the side wall stock. .Only such upward 'How will occur as is commensurate with the relatively light pressure necessary .to be maintained upon the unformed' mass, and such stock as flows upward is subsequently brought back down to its ultimate position by the'econtinued downward movement of the mold.

The bottom-pressing memberis preferably kept heated, by means of the pipes 24,25, and the mandrels4 and molds arepreferably used while they are still warm from a preceding vulcanizinr operation. I lind in practice that the? est. results j are obtained when thestock and mshaping members are at such temperature that the stock adheres to` the shaping members and extends itself by internal flow, its cohesive properties-being weaker than its adhesion to the shaping members. The sheets ofY partition -stock, between the mandrelsare preferably at not such high temperature as to be extended trom between the mandrels by the pressure in the ymass of stock 55. An advantage of my invention is that the jar may be formed without the high pressure, such as to displace or extrude the4 partition sheets, which would be required to form the jar in an ordinary plunger-mold operation.

While the vents 92 may be dispensed with as to molds of but slightly uneven surface, I prefer to employ them where the recesses to be lilled are deep, as in the molds here shown.

When the mold has been moved downward to its final position upon the mandrels, the ram 11, vwith the mandrel-supporting plate 34 thereon, is allowed to descend of its own weight, by exhausting the cylinder 10, leaving the mold, with the work and the inandrels therein, suiported by tlic turret'i'l, the mold and wor t leaving the bottoni-pressing member 17 and descending onto the turret as the ram is withdrawn. The bottompressing plate 31 may adhere to tlie work by suction and thus be ydetached from the spring clamps 30, or it may be so detached by hand, to be used as a mold member in the vulcanization of the jar.

The mold assembly, with the work therein, is then removed and put through the vulcanizing operation, and the molding operation as described is repeated. The mold, be-

ing made in the four sections, may readil i'.

be removed'from the battery jar aftervu canization, notliwitlistanding the undercut.

form of the handle-molding recesses.

The apparatus is adapted for the rapid forming of jars in association with vulcanizing molds and mandrels, but little preforining of thestock is required, good cohesion of the stock is obtained without requiring extremely high pressure, and the jars are molded accurately to form.

An advantage of employing yielding ymeans such as the fluid pressure cylinder 11i-for driving the.- mold isthat the pressure on the mold and on the mandi-els readily may be so correlated as to conform to the plasticA characteristics of the stock and avoid such rapid movement of the'm'old, for eX- ample, as would result iniindul attenuating or tearing the growing wall o stock. This advantage is of especial importance where,

as here, the moldis formed with a recessed surface interlocking with the stock.

Modifications vmay be resorted to withoutdeparting from the scope of m invention,

and I do not wholly limit my c aims to the specific procedure or apparatus described.

I claim:

1. 'Ihe method of sha ing a cellular article of plastic material) which comprises assembling a partition forming sheet of stock between mandrel members and flowing an unformed mass of stock, by pressing 1t against the mandrel assembly, into the form ,o a coating upon the latter, and so joining sidt coating with said partition forming s ee 2, The method of shaping. af cellular article of plastic material which comprises asso moved.

seinbling a partition forming sheet of stock between mandrel members and applying a coating of stock to the mandrel assembly by pressing a mass of stock tliereagainst, and moving a shaping member along with and holding it against the .flowing stock as the latter extends itself upon the surface of the mandrel assembly.

3. ll`he method of shaping an article of plastic material which comprises applying :i coating of plastic stock to a shaping structure by pressing a mass of stock thereagainst ivhile moving ay shaping member of recessed surface along with and pressing it against the flowing stock as the latter extends itself upon thc surface of said shaping structure, and venting the recessed surface of said shaping member through said member.

4. Apparatus for shaping plastic material, said apparatus comprising a set of at least three rigid shaping members substantially enclosing a. stock-receiving space and adapt- -cd for relative movement to effect a radical 'change Vof tlic sha e of said space to that of the article to beorined, one of said members being movable along with, and at ap- 'iroximately thesaiiie speed as that of, the

owing stock adjacent thereto, and fluidteirculatiiig means for heating a. mass of stock in said stock-receiving space during the described relative movement of the sai members.

5. Apparatus for shaping a cellular article of plastic material, said apparatus comprising a mandrel structure having a'partitionmolding recess, means for pressing a mass of stock against said mandrel structure to flow the stock there-about, and. a shaping member relatively movable along said pressiiig...means and said. mandrel structure and adapted therewith to press the stock while 6. Apparatus plastic material, vsaid apparatus Vcomprising a shaping member, means for pressin a mass of stock against said shaping mem r to flow it into the form of alayer thereon, and a shaping member relatively movable along said pressing means and the first said shaping member and adapted therewith to press the stock while so moved. one of said shaping members being formed with a recess'ed shaping surface and with a vent aper ture therethrough at its recessed portion.

7. Apparatus for shaping anarticle of1 plastic material, said apparatus comprising a shaping member formed with a recessed shaping surface and with a vent aperture at its recessed portion, and means for so comressing a mass of stock vand relatively moving it along said shaping surface as to cause the stock to be given off and pressed against the latter.

8. Apparatus for shaping an article. of plastic material, said apparatus comprising for shaping an article ofl inil y relatively moved past said pressing inema recessed shaping member, a pair of press ing members for so compressing a mass of stock in contact with said shaping member as to cause the stock to be given ofi' as a layer upon said shaping member as the latter is relatively moved past said` pressing inem-` bers, and yielding means for so lmovlng said shaping member with relation to both of said pressing members.

-9. Apparatus for shaping an article of plastic material. said apparatus comprising a shapinginenibei, a pair of pressing members for 'sc eompressing a mass .of stock in contact with said shaping member as to cause the stock to be given ofl' as a4 layer upon said shaping member as the latter is bers, and yielding means for so'inoving said shaping member with relation to both `of said pressing members.

10. Apparatus for shaping an 'article of plastic material, said apparatus comprising a vsecti-onal female shaping structure, a pairv of opposed, male, stock-pressing members telescoped within said female member, said female member being adapted for'axial movei ment with relation to both of said male members during the shaping operation, and means for circulating a heating' fluid in one of said male members.

11- Apparatus for shaping an article of plastic material, said apparatus comprising a female shaping structure, anda pair of opposed, male, stock-pressing members tele-- scoped within said female structure, the latter being aizially'movable with relation to adjacent its ends, and a pair of opposed,

male, stock-pressing members :telescoped within said female structure and slidably L fitting said flanges, said female l structure being axially movablewith relationto both of said male members. Y

13. Apparatus for shaping an article of plastic material, said apparatusv comprising a downwardly projecting, male, stock-pressing structure, a second male, stock-pressing structure adapted to be opposed to the first said structure from belowto press a mass of stock between the two, and to be lowered' therefrom, a separate, unattached, female shapingstructure adapted to be moved in telescoped relation to the two opposed male structures, and supiporting means adapted freely to' receive an to support said female structure bef-Ween said male structures `when the lattcrvare separated, and to Vraise' said female structure into telescoped relation to the first mentioned male structure.V

il, Apparatus as defined in Claim 13 in which the supporting means comprisesa turret adapted to carry the female shaping the sepamemberl into the space between rated male members. v

15. Apparatus for shaping an article of plastic material, said apparatus comprising a downii'ardly projecting, male, st0cli-press ing structure, a vertical plunger below said structure adapted to raise a mandrel towardplastic material, said apparatus comprising a downwardly projecting, male, stock-press# ing structure, a vertical plunger below saidstructure adapted to raise a mandrel toward the latter, a female shaping structure adapted tobe moved in telescoped relation-to said stock-pressing structurepand means for Supporting a mandrel structure in position to be picked up by said plunger structure as the latter rises, said mandrel supporting structure comprising a support adapted to be cleared by the rising plunger. and a member adapted to support a plurality of mandrels, to rest. on saidsupport, and to be picked up therefrom b v said plunger.

18. Apparatus for shaping an article of plastic material, said apparatus comprising a downwardly projecting, male, stock-pressing structure, avertical plunger below said structure adapted to raise a mandrel toward the latter, a female shaping structure adapt' ed to be moved in telescoped relation to said stock-pressing structure, .a pivoted member yadapted to carry a mandrel structure intov position to be picked up by saidplunger as the latter rises, mandrel positioning means on said pivoted support, and fixed mandrel positioning means adapted to cooperate with the positioning means on said pivoted sup-` port as the latter' is swung to mandrel delivering position, to position the lmandrel. structure for the operation of saidplunger.

19.'Apparatus for shaping an article of plastic material,l said apparatus comprising a throii'gh-apertured, female shaping member, a pairof opposed, male, stock-pressing members within Isaid female` member, `each lli ofthed three members being axially movable CFI with relation to the other two, and a stockpressing plate detachablyl secured to the face of one of said male members.

20. Molding apparatus comprising a set of rigid molding members adapted completely to close a stock-receiving space, except as to air-venting spaces, by contact of smooth, rigid surfaces thereof, three members of the set being ada ted for relative movement of each with re ation to each of the other two during thelshaping operation and by such movement radically to change the shape of stock in the said space while maintaining the complete enclosure thereof, except as to air-venting spaces by the said rigid members.

21. The method of making an article from moldable material which comprises completely enclosing a mass of the materlal,

except as to air-venting spaces, with at least 20 three rigid molding members and so moving each of three of said members with relation to each of the other two during the sha ing operation as radically to change the s ape of the said mass of material lwhile keeping '25 it completely enclosed except as to air-venting spaces by Contact of the said rigid molding members with each other.

In Witness whereof I have hereunto set my hand this 17th day of May, 1924.

' FRANK MACDONALD 

